Dopamine D1-receptors modulate lateral inhibition between principal cells of the nucleus accumbens.

One of the current hypotheses on dopamine in the physiology of motivation posits that this neurotransmitter regulates filtering and selection of inputs to the nucleus accumbens. The effects of dopamine (100 microM) and the D1-receptor agonist SKF 38393 (20-50 microM) on GABAergic synaptic transmission between pairs of principal cells of rat nucleus accumbens were studied by using simultaneous dual patch-clamp recordings in acutely prepared brain slices. Both compounds attenuated postsynaptic responses induced by presynaptic firing and this effect was reversed by the D1-receptor antagonist SCH 23390 (25 microM). This attenuating effect of dopamine D1-receptors may act to diminish competitive interactions between single projection neurons or ensembles in the nucleus accumbens.